MORE than a thousand people were ordered to stay indoors and keep their windows and doors shut after gas escaped from Runcorn's giant chemical plant.

Chlorine gas drifted over homes following a pipeline leak at the Ineos Chlor plant in Weston shortly after 9am on Friday.

The leak came just days after Ineos claimed it needs £635m to improve out-of-date equipment ­ including the cellrooms used to manufacture chlorine ­ at the plant.

Cheshire police immediately issued a warning to residents, instructing them to keep their doors and windows shut tight.

The emergency Operation Cloudburst was launched as fire engines and paramedics went to the scene. A drop-in centre was set up for anyone who believed they may have become contaminated.

Roads in the area were sealed off and the Runcorn-Widnes bridge became gridlocked after the Weston Expressway was shut.

Two schools near the plant ­ Weston Point Primary and Weston County Primary ­ were ordered to keep children indoors. Other schools in the town also elected to keep pupils inside for fear of the leak spreading.

Residents were warned the gas could cause breathing problems and skin and eye irritation, and doctors were put on alert for possible casualties.

There were no reports of injuries, but some residents claimed they had felt the acrid gas filling their throats.

But Ineos says the leak was small and easily contained by the emergency services.

A spokesman told the Weekly News: 'Ineos Chlor very much regrets the incident that occurred at its Runcorn site. We sincerely apologise for any inconvenience caused to local residents.

'The incident consisted of a small release of chlorine from a plant on site which has now been made safe. There will be a full and thorough investigation and the plant will not be restarted until we are satisfied that corrective actions have been put in place to prevent a recurrence.

'The incident was efficiently and effectively dealt with without injury.'